This thesis tries to consider all essential factors for developing a fuel sensor. The final device should be able to analyze mixtures of diesel, bio diesel, gasoline and other fuels. A number of possible detection methods is considered and the most relevant detection methods as well as the necessary components are discussed in greater detail. Furthermore a way to determine the measurement result by combining the measured parameters is discussed. The characteristic parameters of the substance to be analyzed are determined and initial tests are performed. In the end a series of measurements is conducted with a prototype device. The thesis concludes by proposing future development steps.